The story of the Welsh mining village of Aberfan is well known across the globe of to those of a certain age, less known amongst those under 30. But the story is one that should be remembered; not only to remember those who needlessly lost their lives, but ensure the lesson from the accident remains.

What happened?

The disaster unfolded on October 21st 1966, after millions of cubic metres of excavated mining debris from the Merthyr Vale Colliery, lodged onto the side of Mynydd Merthyr hill, came thundering down the hillside onto the village of Aberfan below. Pantglas Primary School took the full hit; 150,000 tonnes of coal slurry killed 116 children and 28 adults. A whole class of 34 juniors were among those who perished. But five children were miraculously dug out alive after they had been shielded from the brunt of impact by dinner lady Nansi Williams.

Warnings

Letters addressed from DCW Jones, the Merthyr Borough and Waterworks engineer, to Mr D Roberts, area chief mechanical engineer for the National Coal Board, and TS Evans, the town clerk, dated back as far as August 1963, all carry the same subject line: “Danger from Coal Slurry being tipped at the rear of the Pantglas Schools.”

DCW Jones clearly outlines the reasons in these letters as to why ‘tip No 7’ [the name of the debris pile] shouldn’t continue to be used. He cites previous movements after heavy rain and the fact that the absorption of storm water would counter any attempt to de-water the slurry before it is tipped. He also prophesies, in restrained, official language, what would happen if the tip did collapse. In August 1963 he concludes with the line, “…if they were to move a very serious position would accrue”. In December of the same year he warns again that “although the current solution at Pantglas may be difficult it will not by any means be as difficult as would apply in the event of the tips sliding in the manner that I have envisaged”.

In March 1964, DCW Jones received a reply from the National Coal Board stating that with regard to the disposing of slurries they “would not like to continue beyond the next 6/8 weeks in tipping it on the mountainside where it is likely to be a source of danger to Pantglas School”.

In January of 1965, two mothers had presented a petition to Pantglas headmistress Ann Jennings about flooding – which she then passed on to the local council.

Yet still, Tip No 7 remained in use until its collapse.

A terrible lesson learnt

The disaster had been caused, the following tribunal stated, not by “wickedness but ignorance, ineptitude and a failure of communication”. Nobody lost their job or faced punishment.

It is a lesson that can be used in regards to a number of activities; the basics being that if you dig a hole and pile the contents onto the edge, at some point it will collapse. It will also happen at a faster rate if other conditions, such as water, are present.

A BBC documentary commemorating the disaster, “The Green Hollow”, will be broadcast by BBC1 Wales on Friday 21 October, 9pm, and on BBC4 on Sunday 23 October, 9pm.